Syrian activists say Islamic State (IS) fighters have seized territory from rebels in an area close to the Turkish border.

The British-based Syrian Observatory for Human Rights reported on May 27 that the militants captured a number of villages around the town of Marea, north of Aleppo, and almost fully encircled the rebel-held town.

The advance also brought the IS group closer to Azaz, a town 6 kilometers from Turkey.

Rebel groups battling the IS group in the area have been supplied with weapons via Turkey.

The IS offensive comes as the group is under pressure in northeastern Syria, after Kurdish forces and their allies launched an attack this week north of Raqqa, the militants' de-facto capital city.